Polypropylene strapping is the most commonly used and least expensive of all strapping materials. It's light and easy to apply and recycle. Characteristics include high elongation and elongation recovery, but low retained tension. Available in both manual and machine grade, it can be sealed with buckles, seals, heat seals or friction welds. Polypropylene is best for light duty palletizing, unitizing, carton closing and bundling. It is used in all semi-automatic strappers and nearly all stand alone arch machines.